“Pig” MRSA – are the pigs really to blame?

February 23, 2012

Photo by Keith Weller

There is a strain of MRSA (methicillin-resistant Staphylococcus aureus) that has been tracked passing from pigs to humans. It was always thought that the MRSA initially came from the pigs, but new research published in mBio (open access) suggests that pigs might not be the original source.

Instead it looks like the strain may have originated in humans but been methicillin-susceptible. It then at some point passed into pigs where it picked up some antibiotic resistance genes from other bacteria before then going back into humans (especially farm workers and others who have close contact with pigs) as a more dangerous strain.

Unfortunately antibiotic resistance is one of the problems we face when bugs (in the sense of pathogens, rather than insects!) can so easily share and swap their genetic material.

One of the co-authors on the paper, Tara Smith has written an interesting post about it over at her blog, Aetiology which is well worth a read. (If you’re interested in antibiotic resistance, public health and epidemiology her blog is definitely one to add to your RSS feed.)